Percentage Calculator
Calculate percentages instantly: find what a percentage of a number is, what percentage one number is of another, percentage increase or decrease, and more — pick a mode below.
Result
Enter values above to see your result.
Examples
| Question | Calculation | Result |
|---|---|---|
| What is 20% of 50? | (20 ÷ 100) × 50 | 10 |
| 25 is what % of 200? | (25 ÷ 200) × 100 | 12.5% |
| Increase from 50 to 75 | ((75 − 50) ÷ 50) × 100 | 50% increase |
| Increase 200 by 10% | 200 × (1 + 10 ÷ 100) | 220 |
Formula & Methodology
Each mode uses a different rearrangement of the core percentage formula:
percentage = (part ÷ whole) × 100The calculator substitutes your X and Y values into the formula for the selected mode and shows the substituted calculation alongside the result.
How to Use
- Choose the calculation type that matches your question.
- Enter the X and Y values the mode asks for.
- Press Calculate (or just keep typing — the result updates automatically).
- Copy the result or share a link to this tool if needed.
Frequently Asked Questions
How do I calculate what percentage one number is of another?
Use mode "X is what percentage of Y?". Divide X by Y and multiply by 100. For example, 25 is 12.5% of 200.
What is the difference between percentage increase and percentage difference?
Percentage increase/decrease is directional and measured against a starting value (X). Percentage difference treats both values symmetrically, dividing by their average — useful when neither value is clearly the "original".
Why do I get an error for some inputs?
A few modes divide by the starting value (X) or by Y. When that value is zero, the calculation is mathematically undefined, so the tool shows an error instead of a misleading result.
Can I use negative numbers?
Yes. Percentages and values can be negative where mathematically meaningful, such as a percentage decrease that results in a negative value.
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